Patrick Finn fibbed about his age in order to join the U.S. Marine Corps a bit earlier than he should have. He served honorably and was ready to end his service before the Korean War ever began. But his inability to come up with $92 led him to re-enlist and in the summer of 1950 he was off to fight a war in a place he knew nothing about.

The summer of 1950 was chaotic in Korea. The North Koreans invaded the south in late June and nearly conquered the whole peninsula. But U.S. forces arrived just in time, pushing out from the Pusan Perimeter and executing the very successful Inchon Landing. Within a couple of months, U.S. forces thought they would be home by Christmas.

But in late 1950, just as the U.S. and our allies had pushed the North Koreans back to the Yalu River, Chinese forces came swarming across the border, inflicting severe American casualties, taking many troops prisoner, and surrounding U.S. Marines at Chosin Reservoir.

In this edition of "Veterans Chronicles," Patrick Finn describes the surprise of the Chinese onslaught, the brutally frigid temperatures at Chosin Reservoir, how the Marines fought while surrounded, and what it was like to fight hand-to-hand. Mr. Finn also reflects on the proce of our freedom and tells us why returning to Korea in recent years was such a powerful experience.